ZWC don't show messages with empty field "to" in Drafts folder

Release 8.0.4.GA.5737.UBUNTU12.64 UBUNTU12_64 FOSS edition.
On one of the accounts listed problem: ZWC don't show messages with empty field "to" in Drafts folder. Count of mesages in folder Drafts is correct.
I tried it with different computers, browser Chrome and IE8. In ZWC HTML mode problem messages are shown.
If folder Drafts is shared for another account, then this account sees the messages completely. If I fill field "to" in the message, then message will become visible.
How to fix it?

I'm curious about this since I've seen this on occasion with a few accounts and other folders. There is a count indicator in the folder but nothing inside I can see.

If you change the mailbox to HTML instead of Advanced (Ajax) in the account preferences and refresh the page do you see the message? That was the only way I could get a message there but not visible to show up.

Yes, I see the message, if I change the mailbox to HTML in the account preferences and refresh the page. But it is on this account requires a "drug-and-drop" mechanism for file attachments.
And I see the message under another account, if I shared folder for this account.